Removed unneeded imports
Wrote enumeration of vect_n_k and cut_n_k
added is_row_take and is_row_drop
Working plactic congr + RS -> plact
Removed unneeded inhabitant from is_row_rcons
renamed -> set_nth_LxR
Added max, maxL and rembig theory
Added congrruleP lemma
Various lemma on maxX and maxL
Added gencongr_homog
Final plactic theorem (still needs 1 lemma + Green's invariants
Various minor cleanups